Do dogs change after being neutered or spayed?

May 3, 2023 - 6 min read
terrier dog in sweater on tan and white background

As a dog owner, one of the most important decisions you’ll make is whether or not to spay or neuter your furry companion. 

It’s one thing if you’re planning on breeding your papered, healthy Papillon. But if you’re like most dog owners, there are plenty of benefits to having your pet spayed or neutered — and they likely outweigh any downsides.  

Not only do spaying and neutering your dog eliminate the possibility of unwanted litters and offer some health benefits, but it could also extend your best friend’s life. On average, spayed dogs live 26% longer and neutered dogs lived 14% longer

So why do many pet parents struggle with this decision? 

Why the Decision to Spay or Neuter Your Dog Might Be Tough

You might have heard rumors that spaying or neutering your dog will completely change their personality for the worse. If you’ve fallen in love with your pup, it might feel scary to risk changing their personality.

On the other hand, you might also hear from some dog owners who insist that spaying or neutering was the panacea that cured their dog of their incessant marking behavior and fierce hatred of mailmen.

So which of the rumors are true? Will your energetic Aussie shed his love of hiking and become a mopey couch potato? Or will your anxious Cockapoo take a chill pill and stop peeing on the carpet?  

The truth is, spaying or neutering will likely result in some changes in your dog. But rather than focusing on sensational stories, let’s get into the facts. Here’s what you need to know about how neutering can affect your dog's behavior and health.

Spaying/Neutering Differences Between Male and Female Dogs

First, let’s tackle the basic differences between male and female dogs when it comes to spaying and neutering, and the potential impact on their overall behavior and health:

Sterilization in male dogs — called neutering –– involves the removal of the testicles, which decreases the production of testosterone. Testosterone is the hormone responsible for many male dog behaviors, including aggression, marking their territory, and humping. Without this hormone, your dog may become less dominant and less likely to engage in these behaviors.

Sterilization in female dogs — called spaying — involves the removal of the ovaries and uterus, which eliminates their heat cycles. During these heat cycles, female dogs may become restless, anxious, and more prone to wandering. By eliminating heat cycles, spaying can help reduce these behaviors as well as the risk of certain types of cancer and other health issues.

How Do Spaying and Neutering Impact Dogs’ Behavior?

Now let’s talk about behavioral effects. Will your typically guardian-like German Shepherd become abnormally friendly? Will your goofy, precious Pug lose their sense of humor?

There’s no denying that spaying or neutering may cause a few changes, but you might find many of these changes to be welcome.

Your Dog May Be Less Aggressive

After spaying or neutering, one of the most noticeable changes in both male and female dogs is a decrease in aggression. That’s because, as we mentioned before, spaying and neutering decrease hormones that can contribute to aggressive behavior — namely, testosterone in male dogs and estrogen in female dogs.

However, it’s important to note that spaying or neutering alone may not eliminate aggressive behavior in all dogs. A variety of factors —  including genetics, upbringing, and proper socialization — all come into play. 

While spaying and neutering can help decrease the intensity of these behaviors, they’re not a cure-all solution — so don’t assume your standoffish Chihuahua will suddenly take a shine to that French Bulldog next door!

Your Dog May “Mark” Less After Neutering

Another common behavior change that owners may notice after sterilization is a decrease in marking behavior. Marking is when a dog urinates in small amounts to “mark” their territory. 

Male dogs are more prone to marking than female dogs, and neutering can help decrease this behavior. But you can’t simply assume that neutering will solve the issue of a perpetually wet couch. 

If basic training isn’t working to eliminate the issue of marking, see your vet. Persistent marking can be rooted in anxiety, stress, or other medical conditions.

Your Dog May Be Less Energetic

Spaying and neutering can also have an impact on your dog’s energy and activity levels.  

Some dogs may become less active or less interested in play after neutering, while others may become more relaxed and content. It’s difficult to predict exactly what will happen in each case, particularly if your dog is chock full of energy. Ultimately, the effort you put into training your dog from a young age will have the greatest impact on their personality. 

To ensure they’re receiving the appropriate amount of physical activity after they’ve been spayed or neutered, monitor your dog’s current activity level and adjust their exercise routine appropriately. That may mean more exercise — or less. 

Your dog’s pain medication, not to mention the cone of shame, will put a damper on things immediately after the procedure. Your vet will likely advise you to take things easy for a few days. 

Your Dog May Be More Prone to Weight Gain 

Spaying or neutering won’t just potentially increase your dog’s lifespan; it could also increase their size.

Sterilization can contribute to obesity in dogs, as they may have a decreased metabolism and require fewer calories after the procedure. But inadequate exercise and unhealthy diets may also be contributing factors. It’s usually possible to help an overweight dog lose weight, whether they’ve been sterilized or not. 

It’s important to monitor your dog’s weight and adjust their diet and exercise routine as necessary to maintain a healthy weight. Consult your vet if you need help. 

Your Dog’s Coat and Skin Health May Be Affected 

Without the hormones produced by the reproductive organs, some sterilized dogs may experience changes in their skin and coat. Dogs who were low maintenance might suddenly have dry, flaky skin or a dull, lackluster coat, especially if you’re not grooming or feeding them properly. 

So after your dog’s been spayed or neutered, it’s more important than ever to provide them a healthy, balanced diet and regular grooming. 

In Some Cases, There’s Such a Thing as Too Early

Recent research has found a greater risk of joint problems in large-breed dogs who are spayed or neutered at too young an age. There’s also a greater risk of incontinence in female dogs who are spayed too early.

Generally speaking, small breeds can be spayed or neutered earlier than larger breeds. Speak to your vet to determine when you should spay or neuter your dog.

The Bottom Line

Spaying and neutering can have a very positive impact on your dog’s behavior — and extend their lifespan. But it’s important to remember that every dog is unique, and you’ll likely find that your pup’s personality will shine even brighter post-procedure. 

But if you’re hoping for a miraculous transformation away from negative behaviors, don’t get your hopes up. Spaying or neutering are not a one-size-fits-all solution or a substitute for proper exercise and dog training. Above all, it’s important to work with your veterinarian — and, if necessary, a certified behavioral trainer — to determine the best course of action. 

Does Pet Insurance Cover Spaying or Neutering?

The short answer: No; pet insurance typically does not cover spaying or neutering. While sterilization clearly has health benefits, it’s considered an “elective” procedure. ManyPets does not cover these procedures under dog insurance or under our Wellness Plan.

That being said, our Wellness Plan covers up to $600 total for preventative treatments that typically aren’t covered under insurance policies, including routine checkups, vaccinations, flea and heartworm medications, and dental cleanings*. 

*Refer to your Wellness Plan and/or Accident & Illness Policy for coverage details and exclusions.


Leanna Zeibak
Content Manager

Leanna Zeibak is a Content Manager at ManyPets. In her spare time, she paints pet portraits and bakes far too many chocolate chip cookies.